Typically, since an electric motor in an electrically drivable off-road dump truck generates a large amount of heat, the electric motor is cooled by a cooling air fed from a cooling blower. Such an electric motor is housed inside a rear axle suspended from a vehicle body frame. The cooling air from the cooling blower is fed to the electric motor inside the rear axle through a duct exclusively used for the cooling air (see, for instance, Patent Literature 1).
Moreover, there has been known a dump truck with use of all-wheel drive by driving all tires using respective electric motors (see, for instance, Patent Literature 2).
Further, a hydraulically drivable off-road dump truck has been known. In such a dump truck, a hydraulic motor is integrated with a pivotally movable yoke forming a suspension for each of the tires. The tires are configured to be driven by respective hydraulic motors (see, for instance, Patent Literatures 3 and 4).